Chemical-mechanical polishing (CMP) is a process of removing material from a semiconductor wafer or other work piece to create a smooth planar surface. Typically, a combination of chemical reaction and mechanical force is used to remove material from a front surface of the work piece to thereby create the planar surface. In a conventional CMP assembly, the work piece is secured in a carrier head such that the surface to be polished is exposed. The exposed surface of the work piece is then held against a polishing pad or other surface that is generally mounted to a rigid platen. Typically, a polishing slurry is introduced onto the polishing surface of the pad, and the work piece and/or polishing pad are moved in relation to each other in a linear, circular, orbital or other fashion to polish or planarize the surface of the work piece as desired.
Frequently, slurry is supplied to the polishing surface through one or more holes in the polishing pad. These holes typically receive fluid via a common delivery line from a fluid supply source. In many implementations, a manifold or similar structure equalizes fluid resistances for the various paths flowing to the different holes. While the manifold structures found in many implementations have been beneficial for many purposes, the complex design of such structures can create certain limitations and other issues. In particular, the number of holes that can be supported by any particular manifold can be relatively limited, thereby creating issues in distributing slurry and/or creating even flow across the surface of the polishing pad.
It is therefore desirable to create polishing structures and techniques that are able to improve the uniformity of slurry delivery across the surface of the pad. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.